Method and apparatus for conveying parts

ABSTRACT

An apparatus for conveying parts for use with parts with projections the protruding part of which is formed on either the upper side or the lower side as seen in the direction of height, has a regulating member ( 17 ) comprising a regulating portion of a width for preventing passage of the protruding part ( 11 ) of the part ( 10 ) and a non regulating portion ( 19 ) of a width allowing passage of the protruding part ( 11 ), to prevent passage of a part placed upside down in the case where such part is transferred.

TECHNICAL FIELD

[0001] The present invention concerns a technology for conveying partsby aligning them in prescribed orientation by preventing passage ofparts placed upside down. More specifically, this technology can beutilized for aligned conveyance of parts with projection the protrudingpart of which is formed on either the upper side or the lower side asseen in the direction of height as with a projection nut.

BACKGROUND ART

[0002] In the case where projection nuts having projections for welding,for example, are fed from a parts feeder, the projection nuts arearranged in a certain orientation of surface or back face before goingout of the parts feeder. However, there are cases where the parts arefed out upside down for some reason or another and, to prevent them frombeing fed in a wrong state, a control method is known which consists indetecting the height of the parts and letting pass normal parts onlywhile stopping unusual ones.

[0003] In the case where the two sides are discriminated based on theheight of the parts conveyed, control may be easy if there is anappreciable difference in height between the parts looking upward andthose looking downward but, if the difference in height isinappreciable, it is necessary to delicately adjust the space in heightof the member which regulates the parts. For example, a projection nutgenerally has projections for welding formed at 4 corners of a squarenut, and the quantity of protrusion in the direction of height of eachprojection is comparatively small while, in the direction of breadth, aquantity of protrusion larger than that in the direction of height isset. Therefore, in the case where the two sides are discriminated basedon the height of parts, fine adjustment of the regulating member israther difficult and even a slight deviation of adjusted value may makethe discrimination impossible, thus letting pass parts which are placedupside down. Moreover, in the case of parts having hardly any differencein height between the upward looking state and the downward lookingstate, it is simply impossible to perform any control of passage basedon the parts height.

DISCLOSURE OF INVENTION

[0004] According to an embodiment of the present invention, the methodfor conveying parts comprises the steps of connecting a parts feeder toa parts supply unit, providing a parts transfer passage for transferringparts with projections the protruding part of which is formed on eitherthe upper side or the lower side as seen in the direction of height,disposing, at a position close to the parts feeder of the transferpassage, a regulating member for preventing passage of a part placedupside down in the case where such part is transferred, disposing aparts sensor at a position close to the supply unit of the transferpassage, detecting, with the parts sensor, reduction in the number ofparts on standby between the parts sensor and the supply unit in thecase where the passage of parts is prevented by the regulating member,operating the parts feeder with this detection signal, and issuing anabnormality signal in case no part is detected by the sensor afterpassage of a certain time from that operation.

[0005] By issuing a signal, with such operation, in case no supply ofparts on standby is started even with passage of a certain time afterthe passage of parts placed upside down is prevented by the regulatingmember, it becomes possible to either give an alarm such as buzzer orlamp, etc. by using this signal or stop the operation of the partsfeeder, and this is effective for reduction of noise and saving ofelectric power. In case no supply of parts on standby is made withpassage of a certain time while the parts feeder continues working, itis possible to either stop the operation of the parts feeder or give analarm to notify an abnormality by judging that the parts are preventedby the regulating member, and thus take remedial measures such asremoval of unusual parts, etc.

[0006] According to another embodiment of the present invention, themethod for conveying parts comprises the steps of connecting a partsfeeder to a parts supply unit, providing a parts transfer passage fortransferring parts with projections the protruding part of which isformed on either the upper side or the lower side as seen in thedirection of height, disposing, at a position close to the parts feederof the transfer passage, a regulating member for preventing passage of apart placed upside down in the case where such part is transferred,disposing a parts sensor at a position close to the parts feeder of thetransfer passage and on the downstream side of the regulating member,and issuing, in the case where the passage of parts is prevented by theregulating member, an abnormality signal in case no part is detected bythe sensor after passage of a certain time after the part immediatelybefore the prevented part was detected by the parts sensor. Here also,an abnormality signal is issued in case a part is prevented by theregulating member, and it becomes possible to either give an alarm suchas buzzer or lamp, etc. or stop the operation of the parts feeder byusing this signal, and this is effective for reduction of noise andsaving of electric power.

[0007] According to other embodiment of the present invention, theapparatus for conveying parts is designed for transferring parts withprojections the protruding part of which is formed on either the upperside or the lower side as seen in the direction of height by aligningthem in prescribed orientation, and comprises a regulating member forpreventing passage of a part transferred in the state upside down. Theregulating member performs regulation and control in response to theprotruding part formed on either the upper side or the lower side of thepart, and allows passage of parts in normal orientation only. Therefore,passage of parts placed upside down can be prevented without fail.

[0008] The regulating member may have a regulating portion of a widthfor preventing passage of the protruding part of the part, and a nonregulating portion of a width allowing passage of the protruding partdisposed at the top and at the bottom. This makes it possible to preventpassage of a part placed upside down the protruding part of which iscaught by the regulating portion. On the contrary, in the case where theprotruding part corresponds to the non regulating portion, the part isallowed to pass through. By thus installing the regulating portion andthe non regulating portion in a fixed way, it becomes unnecessary tomake any fine adjustment as in the prior art, and this helps to greatlyimprove the working accuracy and simplify the daily control at the sametime. Furthermore, even in the case where there is hardly any differencein height of the parts whether they are placed in the upward lookingdirection or downward looking direction, passage of any parts in unusualdirection can be prevented because of the relation between theregulating portion and the non regulating portion, enabling applicationto a wide range of parts with high utility.

[0009] The apparatus may comprise a sorting device disposed on theupstream side of the regulating member, and the sorting device not onlyguides the parts in linkage with the projections of the parts but alsosorts out the parts by discriminating the surface and the back face ofthe parts and dropping parts placed upside down. The sorting device maybe constructed with a portion in which the outside of the spiral passageis low, and a groove of a fixed length formed in the direction oftransfer of parts in the spiral passage. The apparatus may comprise acollecting box for receiving parts dropped by the sorting device, thecollecting box communicating with the inside of the bowl of the partsfeeder.

[0010] The apparatus may comprise an unusual nut discharging devicedisposed on the upstream side of the sorting device, the dischargingdevice being composed of the portion in which the outside of the spiralpassage is low, an upright wall provided on the outer circumference ofthe portion, an opening formed in the upright wall, and an accumulatingbox, positioned below the opening, for receiving unusual parts droppingfrom the opening. In the case where the height of unusual parts issmaller compared with the normal parts, it is desirable to set theheight of the opening higher than the unusual parts but lower than thenormal parts.

[0011] According to still other embodiment of the present invention, theapparatus comprises a parts feeder, a sorting device for discriminatingthe surface and the back side of parts transferred through the spiralpassage of the parts feeder and discharging parts placed upside down,and a discharging device disposed on the upstream side of the sortingdevice.

[0012] The sorting device may be constructed with a portion in which theoutside of the spiral passage is low, and a groove of a fixed lengthformed in the direction of transfer of parts in the spiral passage. Theapparatus may further comprise a collecting box for receiving partsdischarged by the sorting device, the collecting box communicating withthe inside of the bowl of the parts feeder.

[0013] The discharging device may be composed of a portion in which theoutside of the spiral passage is low, an upright wall provided on theouter circumference of the portion, an opening formed in the uprightwall, and an accumulating box, positioned below the opening, forreceiving unusual parts dropping from the opening. In the case where theheight of unusual parts is smaller compared with the normal parts, it isdesirable to set the height of the opening higher than the unusual partsbut lower than the normal parts. Unusual parts are made to drop into theaccumulating box by the discharging device, not to be mixed into normalparts. In this way, unusual parts are prevented from being sent to thedownstream processes.

[0014] In the case of unusual parts the height of which is smaller thanthat of normal ones, discharge of unusual parts can be made accuratelyby utilizing the difference of height. The unusual parts dischargingdevice is characterized in that it is provided with an opening of aheight enabling passage of unusual parts but preventing passage ofnormal parts. In this way, unusual parts are sorted out and dischargedin the state where a difference of height is detected accurately.Especially, since discharge of unusual parts is made on the upstreamside of the point of discrimination of surface and back face, deliveryof unusual parts is prevented even when the unusual parts are placed inthe correct orientation. As an unusual part comes to the control board,this unusual part passes through the opening and drops into theaccumulating box to be kept there, because its height is smaller thanthat of the opening. Therefore, even in case some unusual part isreturned by error into the bowl of the part feeder, it eventually passesthrough the discharging device and is caught in the accumulating box,thus preventing delivery of any defective parts.

BRIEF DESCRIPTION OF DRAWINGS

[0015]FIG. 1 is a partial plan view of the parts feeder showing anembodiment of the present invention;

[0016]FIG. 2 is a simplified plan view showing the general shape of theparts feeder;

[0017]FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

[0018]FIG. 4 is a sectional view taken along the line IV-IV of FIG. 1;

[0019]FIG. 5 is a sectional view taken along the line V-V of FIG. 1;

[0020]FIG. 6 is a sectional view of the portion of air injection nozzlein FIG. 1;

[0021]FIG. 7A is a front view of the regulating member, showing passageof a nut in normal orientation;

[0022]FIG. 7B is a front view of the regulating member, showing a nut inunusual orientation with imaginary line;

[0023]FIG. 7C is a bottom view of the regulating member indicated inFIG. 7A and FIG. 7B;

[0024]FIG. 8 is a front view of a modified example of regulating member;

[0025]FIG. 9 is a side view of another part;

[0026]FIG. 10 is a sectional view showing the mounting of the partssensor;

[0027]FIG. 11 is a simplified view showing a general outline of theparts supply system;

[0028]FIG. 12 is a simplified view showing a general outline of theparts supply system with a modified parts sensor position;

[0029]FIG. 13 is a partial plan view similar to FIG. 1 showing anotherembodiment of the present invention;

[0030]FIG. 14 is a sectional view X-X in FIG. 13;

[0031]FIG. 15 is a side view of a projection nut, the left side showinga normal nut and the right side showing an unusual nut; and

[0032]FIG. 16 is a perspective view of a projection nut.

BEST MODE FOR CARRYING OUT THE INVENTION

[0033] The preferred embodiments of the present invention will bedescribed in detail hereafter with reference to drawings. As form ofparts feeder, there are among others a type in which a round bowl isshaken in two ways by means of a shaking device and a type in which thepart is led by a magnet without shaking, with the former shaking type isgiven as example here. The latter type is described in Japanese patentapplication filed Aug. 7, 1997 and laid open under No. 11-59878, whichis hereby incorporated by reference.

[0034] First of all, reference will be made to FIG. 11 and FIG. 12. Aparts feeder 1 and a parts supply unit 33 are connected to each other bymeans of a parts transfer passage 5. The parts supply unit 33, which isused for supplying the parts or nuts, for example, sent from the partsfeeder 1 to a prescribed point on a steel sheet part 42, is providedwith a supply rod 37 driven forward and backward by an air cylinder 38.The steel sheet part 42 is loaded on a fixed electrode 40 of aprojection welding system 39 provided with a pair of electrodes 40 and41, and the nut is placed on a guide pin 43 of the fixed electrode 40protruding through the steel sheet part, and then the movable electrode41 comes down to weld the nut to the steel sheet part. The electrode 41is constructed in a way to be driven forward and backward by an aircylinder (not illustrated).

[0035] As shown in FIG. 1 and FIG. 2, the parts feeder 1 has a roundbowl 2, under which is disposed a shaking unit 3. On the innercircumference of the bowl 2 is formed a spiral passage 4, and to itsoutlet end is connected a transfer passage 5. The transfer passage 5,which communicates with a relay passage 6 continuous to the spiralpassage 4, is formed with a delivery pipe 7 and a delivery hose 8connected to it, etc. The spiral passage 4 is formed with a guide plate9, and this guide plate 9 forms the relay passage 6 to the transferpassage 5. The guide plate 9 is welded to the inner wall panel 16 of thebowl 2. The part with projections handled here is a projection nut 10 ofsteel, having projections 11 formed at 4 corners of a square nut asshown in FIG. 16. Therefore, the shape of passage of the delivery pipe 7and the delivery hose 8 has a rectangular section as it is apparent fromFIG. 10, etc. As it is apparent from FIG. 1 and FIG. 7A, the projection11 protrudes sideways or in the direction of breadth.

[0036] Over a certain length near the outlet end of the spiral passage4, along the outer circumference of the guide plate 9, is formed afastening groove 12 in the shape of an arch. As one can see from FIG. 3and FIG. 4, the outer circumference side of the guide plate 9 gets lowerfrom the area of the fastening groove 12 toward the relay passage 6. Asshown in FIG. 4, while an upright wall is formed on the outer edge ofthe guide plate 9 in the relay passage 6 from around after passingthrough the fastening groove 12, no such upright wall exists on theouter circumference side of the fastening groove 12. Therefore, in thecase where the nut 10 which arrived in the area of the fastening groove12 is in a posture with its projections 11 down or looking “upward”, theprojections 11 get into the fastening groove 12 and the nut 10 movestoward the transfer passage 5 through the relay passage 6 withoutsliding down from the guide plate 9. In the case where the nut 10 whicharrived in the area of the fastening groove 12 is in a posture with itsprojections 11 up or looking “downward”, the nut 10 is not caught in thefastening groove 12 and, therefore, the nut 10 falls down into thereceiving box 13 from the outer edge of the guide plate 9 and moves downon the sloped bottom plate 14 toward the bottom of the bowl, to bereturned into the bowl 2 through the through hole 15.

[0037] The regulating member 17, which is installed at an optional pointin the longitudinal direction of the transfer passage 5, is illustratedhere for a case in which it is mounted on the upstream side of thetransfer passage 5. The regulating member 17, in stainless steel, iswelded to the guide plate 9, and has a section in the shape of a channelopening in the downward looking direction as shown in FIG. 5. Theregulating member 17 has a regulating portion 18 and a non regulatingportion 19 on its inner side wall. The regulating portion 18 is set insuch a way that the distance between the side wall faces i.e. thedimension of width prevents passage of the projections 11 protrudingsideways from the nut. On the other hand, the non regulating portion 19is set in such a way that the dimension of width allows passage of theprojections 11. Moreover, a slope 20 is formed at the parts inlet of theregulating portion 18, as shown in FIG. 7C, to enable smooth entry ofthe nut 10. The arrow line 21 in this figure indicates the direction ofmovement of the nut 10.

[0038] The disposition of the regulating portion 18 and the nonregulating portion 19 is determined depending on which of the “upward”looking posture and the “downward” looking posture is to be consideredas normal. In the case where the nut 10 must be transferred in theposture with its projections down, the non regulating portion 19 will bedisposed at the bottom and the regulating portion 18 will be placed onit (FIG. 5, FIG. 7A, FIG. 7B). On the contrary, in the case where thenut 10 must be transferred in the posture with its projections up, theregulating portion 18 will be disposed at the bottom and the nonregulating portion 19 will be placed on it (FIG. 8).

[0039] The functions of the regulating member 17 indicated in FIG. 5 arethe following: In the case where the nut 10 is transferred in the normalorientation i.e. in the posture with its projections 11 down, as shownin FIG. 7A, the projections 11 are positioned in the non regulatingportion 19, and the upper side of the square part of the nut 10 ispositioned in the regulating portion 18. Therefore, the nut 10 passesthrough without being caught in any part of the regulating member 17. Inthe case where the nut 10 is transferred in an unusual orientation i.e.in the posture with its projections 11 up, as shown in FIG. 7B, thesquare part of the nut 10 corresponds to the non regulating portion 19,and the portion having the projections 11 corresponds to the regulatingportion 18. As a result, the projections 11 interfere with theregulating portion 18, preventing passage of the nut 10.

[0040] To the downstream side of the regulating member 17 is connected adelivery pipe 7, and to the delivery pipe 7 is further connected adelivery hose 8. The delivery pipe 7 is made of steel sheet while thedelivery hose 8 is made of urethane and, for both of them, the transferpassage 5 has a rectangular section suitable for passage of the nut 10.The supporting arm 27 in the shape of reverse L indicated in FIG. 1 iswelded, at its base 28, to the inner wall plate 16 and to the inside ofthe delivery pipe 7, and the delivery hose 8 is placed on the support 29and fixed by means of a presser fixture 30 with a hat-shaped section.The presser fixture 30 is fixed to the support 29 at flanges 31 by meansof fastening bolts 32.

[0041] This system is so arranged that compressed air is blown into thedelivery pipe 7, to pressure feed the nut 10 toward the delivery hose 8.FIG. 6 indicates the section of this portion, in which a nozzle hole 22is provided in the diagonal direction against the delivery pipe 7, andan air pipe 23 is welded in a way to agree with that hole. The air pipe23 is provided with an air hose 24 (FIG. 1). Therefore, as the nut 10arrives on the downstream side (on the right side in the drawing) of thenozzle hole 22, compressed air is injected and the nut 10 is transferredvigorously.

[0042] To the delivery hose 8 immediately after the delivery pipe 7 isattached a parts sensor 25. Various types of parts sensor may beadopted, but a proximity switch will be taken for example here. As shownin FIG. 10, the parts sensor 25 is put in close contact with thedelivery hose 8 by means of a fixing band 26. The parts sensor 25 issuesa signal when it detected the nut 10 and, in response to that signal,compressed air is injected through the nozzle hole 22 to the nut 10, totransfer the nut 10. Such actions from detection of nut to injection ofair can be implemented easily by means of ordinary air selector valve orcontrol circuit and, for that reason, no concrete explanation on thispoint will be given here.

[0043] To explain the parts supply system indicated in FIG. 11, theparts feeder 1 and the parts supply unit 33 are connected to each otherby means of a transfer passage 5 i.e. the delivery hose 8, and theregulating member 17 is installed at a position close to the partsfeeder 1 on the transfer passage 5. The parts sensor 25 is disposed at aposition close to the parts supply unit 33 on the transfer passage 5,this transfer passage 5 between the parts sensor 25 and the parts supplyunit 33 discharging the function of keeping the parts on standby. Thenumber of parts on standby may be 10 pieces for example, and no signalis issued at all from the parts sensor 25 while either the 10th or 11thpiece is detected by the parts sensor 25. As the nuts 10 which stood ina line up to the parts sensor 25 are consumed by the parts supply unit33, a decrease of the parts between the parts supply unit 33 and theparts sensor 25 is detected by the parts sensor 25, and that signal istransmitted to a shaking unit 34, to put the parts feeder 1 inoperation. However, if a nut in unusual orientation is prevented frommoving by the regulating member 17, it is no use continuing theoperation of the parts feeder 1 and, for that reason, this system isconstructed in a way to stop the parts feeder 1 with passage of acertain time after the start of operation of the parts feeder 1. Forthat purpose, a timer 35 is inserted on the way of the connecting wire36 connecting between the parts sensor 25 and the shaking unit 34. Inthis way, when a signal is issued after passage of a certain time withthe timer 35, the system works to either stop the shaking unit 34 orgive an alarm in response to that signal.

[0044] The parts supply system indicated in FIG. 12 is different fromthat of FIG. 11 only in the place of installation of the parts sensor25. Here, the parts sensor 25 is provided near the parts feeder 1 and inthe transfer passage 5 downstream of the regulating member 17. With suchconstruction, when the nuts 10 are sent out at regular intervals withoutbeing prevented by the regulating member 17, the parts sensor 25 detectsit and sends a signal to the timer 35, which starts counting in responseto that signal. No abnormality signal is transmitted from the timer 35,because the nuts further come flowing one after another and a signal issent from the parts sensor 25 to the timer 35. However, in case a nut inunusual orientation is caught by the regulating member 17, the transferof nuts is suspended for a certain period of time, and the timer 35which started counting in response to a signal from the parts sensor 25issues an abnormality signal, thereby stopping the operation of theparts feeder 1 or giving an alarm.

[0045] The object part for which the present invention is intended hasprojections formed on either the upper side or the lower side as seen inthe direction of height and protruding in both the width in thelongitudinal direction and the width in the transversal direction (referto the shape indicated with two-dot chain line in FIG. 1), andprojection nut is a typical example of such part. On the other hand,even a part 10 in which a round flange 45 is installed under a roundbody 44 as shown in FIG. 9 can also be an object of the presentinvention, the round flange 45 corresponding to the projection.

[0046] In the above-described embodiment, while the surface and the backface of the nuts 10 are discriminated uniformly based on their dimensionof width, there is a fear that, if any unusual nut is mixed there, itmay be delivered without being caught. FIG. 15 indicates comparison of anormal projection nut 10 with an unusual one. In the field of welding,there are cases where the projection 11 for welding remains fallen onthe floor without being molten sufficiently because of a shortage ofwelding current or pressurization. However, it sometimes happens that aworker who picked it up thinks that the nut is a normal one and throwsit into the parts feeder. That unusual nut will be fed together withother normal nuts, but it is supplied normally to the welding machinewithout being prevented by the regulating member 17, if it is in theprescribed orientation. Since that unusual nut is unusual in the heightor shape of the projection 11, it cannot be welded normally, and thusproduces a defect such as incomplete welding, etc.

[0047] Namely, for the discrimination of surface and back face of thenut 10, the so-called “face up” system is generally adopted in which thenut is delivered as it is without falling if only the projection 11 iscaught in the groove 12 of the spiral passage 4. In the case where anunusual nut 10 as shown on the right side of FIG. 15 comes to the groove12 under such condition, that projection 11 is also caught in the groove12 in the same way as a normal projection 11, and is thus sent out inthe form of “face up” as normal product. As described above, a problemis that ordinary discrimination of surface and back face is not enoughin case some projection 11 of unusual shape is mixed even if it is aprojection nut of one same type.

[0048] An embodiment designed for solving such problem will now bedescribed according to FIG. 13 and FIG. 14. As previously described inrelation to FIG. 1 and FIG. 3, a spiral passage 4 of stepped structureis provided around a bowl 2, and this spiral passage 4 is lower on theouter circumferential side. At the end part i.e. outlet end of thespiral passage 4 is formed an arched groove 12 close to its outercircumference, and this is the means for discriminating the surface andthe back face. To the end part of the spiral passage 4 is connected adelivery pipe 7.

[0049] On the upstream side of the groove 12 is installed a sortingmeans 46 for discharging unusual nuts. This is a control plate 47 weldedin upright state on the outer circumference of the spiral passage 4, anda regulating space 48 is formed at its lower part. This space 48, in theshape of a slit extending along the spiral passage 4, is set at a heightallowing the unusual nut indicated on the right side of FIG. 15 to passbut not allowing passage of the normal nut indicated on the left side ofFIG. 15. Namely, because a normal nut and an unusual nut are differentin the height indicated with symbol L, the judgement of passage or notis made with this difference L.

[0050] On the outside of the control plate 47 is installed anaccumulating box 49. This has a structure without any outlet, andunusual nuts falling through the regulating space 48 into this box 49are accumulated there.

[0051] Next, the action of this embodiment will be described. As anormal nut 10 on the left side of FIG. 15 moves along the spiral passage4, the nut 10 comes to the control plate 47 but cannot pass through theregulating space 48 because the height of the nut 10 is larger than thatof the regulating space 48, and it moves toward the groove 12. If anunusual nut 10 on the right side of FIG. 15 comes to the control plate47, this nut passes through the space 48 and falls down into theaccumulating box 49 to be stored there, because the height of the nut 10is smaller than that of the regulating space 48. Therefore, delivery ofany defective nut can be prevented, because an unusual nut which isreturned by error into the bowl 2 gets in the state enclosed in theaccumulating box 49.

[0052] This invention is intended to discharge nuts of unusually lowheight from among nuts of identical dimensions and shape, in the casewhere only projection nuts of one single kind are placed in the partsfeeder, namely unusual nuts the height of which is reduced because ofdeformation of the projections for welding. In other words, the presentinvention functions in the case where a difference of height is producedin one kind of nuts in one same bowl.

1. A method for conveying parts comprising the steps of connecting a parts feeder to a parts supply unit, providing a parts transfer passage for transferring parts with projections the protruding part of which is formed on either the upper side or the lower side as seen in the direction of height, disposing, at a position close to said parts feeder of said transfer passage, a regulating member for preventing passage of a part placed in an unusual orientation in the vertical direction in the case where such part is transferred, disposing a parts sensor at a position close to said supply unit of said transfer passage, detecting, with said parts sensor, reduction in the number of parts on standby between said parts sensor and said supply unit in the case where the passage of parts is prevented by said regulating member, operating said parts feeder with this detection signal, and issuing an abnormality signal in case no part is detected by said sensor after passage of a certain time from that operation.
 2. A method for conveying parts comprising the steps of connecting a parts feeder to a parts supply unit, providing a parts transfer passage for transferring parts with projections the protruding part of which is formed on either the upper side or the lower side as seen in the direction of height, disposing, at a position close to said parts feeder of said transfer passage, a regulating member for preventing passage of a part placed in an unusual orientation in the vertical direction in the case where such part is transferred, disposing a parts sensor at a position close to said parts feeder of said parts transfer passage and on the downstream side of said regulating member, and issuing, in the case where the passage of parts is prevented by said regulating member, an abnormality signal in case no part is detected by said sensor after passage of a certain time after the part immediately before the prevented part was detected by said parts sensor.
 3. An apparatus for transferring parts with projections the protruding part of which is formed on either the upper side or the lower side as seen in the direction of height by aligning them in prescribed orientation, and comprises a regulating member for preventing passage of a part transferred in the state upside down.
 4. An apparatus as defined in claim 3, wherein said regulating member has a regulating portion of a width for preventing passage of the protruding part of said part, and a non regulating portion of a width allowing passage of the protruding part disposed at the top and at the bottom.
 5. An apparatus as defined in claim 3 or 4, wherein a sorting device is disposed on the upstream side of said regulating member, and said sorting device not only guides the parts in linkage with said projection of the parts but also sorts out the parts by discriminating the surface and the back face of the parts and dropping parts placed upside down.
 6. An apparatus as defined in claim 5, wherein said sorting device is constructed with a portion in which the outside of said spiral passage is low, and a groove of a fixed length formed in the direction of transfer of parts in said spiral passage.
 7. An apparatus as defined in claim 5, wherein a collecting box is provided for receiving parts dropped by said sorting device, said collecting box communicating to the inside of the bowl of said parts feeder.
 8. An apparatus as defined in claim 5, wherein an unusual nut discharging device is disposed on the upstream side of said sorting device, said discharging device being composed of a portion in which the outside of said spiral passage is low, an upright wall provided on the outer circumference of said portion, an opening formed in said upright wall, and an accumulating box, positioned below said opening, for receiving unusual parts dropping from said opening.
 9. An apparatus as defined in claim 8, wherein the height of said unusual parts is smaller compared with said normal parts and the height of said opening is higher than said unusual parts but lower than said normal parts.
 10. An apparatus for conveying parts, comprising a parts feeder, a sorting device for discriminating the surface and the back side of parts transferred through the spiral passage of said parts feeder, and discharging parts placed upside down, and a discharging device disposed on the upstream side of said sorting device.
 11. An apparatus as defined in claim 9, wherein said sorting device is constructed with a portion in which the outside of said spiral passage is low, and a groove of a fixed length formed in the direction of transfer of parts in said spiral passage.
 12. An apparatus as defined in claim 11, wherein a collecting box is provided for receiving parts discharged by said sorting device, said collecting box communicating with the inside of the bowl of said parts feeder.
 13. An apparatus as defined in claim 12, wherein said discharging device is composed of the portion in which the outside of said spiral passage is low, an upright wall provided on the outer circumference of said portion, an opening formed in said upright wall, and an accumulating box, positioned below said opening, for receiving unusual parts dropping from said opening.
 14. An apparatus as defined in claim 13, wherein said unusual parts are smaller in height compared with said normal parts, said opening is higher than said unusual parts but lower than said normal parts. 